Movement of cells in ventral hypoblast during mid-gastrulation.
Cells in the hypoblast are moving toward the animal pole and converging toward the dorsal side (away from the side of the embryo that is in view).

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Ventral Hypoblast movie: The animal pole is toward the top, face on view of ventral side (dorsal is on the opposite side of embryo).

Scatter labeling of cells with the flourescent probe, Bodipy-dextran, allows many individual cells to be followed through time. Cells in the ventral hypoblast appear to be spreading away from the plane of view. This is caused by their convergence toward the dorsal side which is 180 degrees away on the opposite side of the embryo. Remember, not all of the cells are labeled in the embryo; the holes that you see between the cells are filled with cells that are not labeled with the flourescent probe.